🔧 Adding

Flyweight Pattern

Author: raj713335

05 Structural Design Patterns/06 Flyweight Design Pattern.py

@@ -0,0 +1,73 @@
+# Flyweight
+
+from typing import List, Dict, Tuple
+
+
+class TreeType:
+    def __init__(self, name, color, texture):
+        self.name = name
+        self.color = color
+        self.texture = texture
+
+    def draw(self, canvas, x, y):
+        print(f"[Drawing] {self.name} tree at ({x}, {y})"
+              f"with color {self.color} and texture {self.texture} on {canvas}")
+
+
+# Flyweight Factory
+
+class TreeFactory:
+    _tree_types: Dict[Tuple[str, str, str], TreeType] = {}
+
+    @classmethod
+    def get_tree_type(cls, name, color, texture):
+        key = (name, color, texture)
+
+        if key not in cls._tree_types:
+            print(f"[Factory] Creating a new treeType: {key}")
+            cls._tree_types[key] = TreeType(name, color, texture)
+        else:
+            print(f"[factory] Reusing existing TreeType: {key}")
+        return cls._tree_types[key]
+
+
+# Context
+
+class Tree:
+    def __init__(self, x, y, tree_type: TreeType):
+        self.x = x
+        self.y = y
+        self.tree_type = tree_type
+
+    def draw(self, canvas):
+        self.tree_type.draw(canvas, self.x, self.y)
+
+
+# Client
+
+class Forest:
+    def __init__(self):
+        self.trees: List[Tree] = []
+
+    def plant_tree(self, x, y, name, color, texture):
+        tree_type = TreeFactory.get_tree_type(name, color, texture)
+        tree = Tree(x, y, tree_type)
+        self.trees.append(tree)
+
+    def draw(self, canvas):
+        for tree in self.trees:
+            tree.draw(canvas)
+
+
+# Demo
+
+if __name__ == "__main__":
+    forest = Forest()
+
+    # Plant many trees but with only 2 types
+    for i in range(0, 10, 2):
+        forest.plant_tree(i, i + 1, "Oak", "Green", "Rough")
+        forest.plant_tree(i + 1, i + 2, "Pine", "Dark green", "Smooth")
+
+    print("\n=========Drawing Forest========")
+    forest.draw("Canvas1")